The present invention is generally directed toward a powder compacting press and, more specifically, to a powder compacting press with a variable speed drive.
The present invention is directed to an improvement on powder compacting presses. Examples of powder compacting presses are disclosed in Applicant""s following issued U.S. Pat. Nos: 3,826,599; 4,047,864; 4,053,267; 4,061,452; 4,061,453; 4,153,399; 4,166,716; 4,230,653; 4,298,563; 4,302,412; 4,347,051; 4,376,744; 4,377,376; 4,390,335; 4,401,614; 4,411,848; 4,427,352; 4,450,127; 4,456,445; and 4,573,895.
In the powder-compacting presses disclosed in the aforementioned patents, powder such as metallic or ceramic powder is compacted and formed in a single or multi-cavity die. The presses tend to be somewhat complicated, including punch and die sets, automatic powder filling means, ejection means, and a heavy duty mechanism designed to move one or more compressing members so as to compress powder trapped in a cavity. All operations of the press are typically controlled by one or more rotary cam shafts which are driven by an electric motor. As a cam shaft rotates, a filling means is moved into place over the cavity. The cavity is either already open and powder fills it, or the cavity is opened up to draw powder into the cavity. An anvil is then moved into place over the cavity, and a compressing member is moved so as to compress the powder in the cavity. The anvil then moves out of the way and the compacted product is ejected or removed from the cavity. This process is repeated to create multiple parts.
In setting up and using a powder compacting press, it is often necessary to slowly move the rotational cam shafts so as to slowly move the machine through its operations. For this purpose, many of the machines typically include a removable hand crank that allows an operator to manually rotate the drive means of the press forwardly and backwardly by small amounts and at a slow rate. The traditional drive motors have not been capable of slowly and controllably moving the cams forwardly and backwardly. In fact, reversing the drive means was inconvenient or impossible. As will be clear to those of skill in the art, the use of a hand crank presented safety concerns. A user could catch their hand or other item on the crank when the electric drive means is operated. Also, manually rotating the hand crank is both slow and tiring. In light of the above, there is a need for an improved powder compacting press which allows for fine control of the press without the need for manual hand cranking.
The present invention improves on the prior art by providing a variable speed powder compacting press. The press includes a generally horizontal table with a powder compacting die cavity defined in the table. The cavity has an upwardly facing opening. A movable compacting punch is disposed in the die cavity and can move upwardly towards the die cavity opening to compact powder disposed in the cavity. A sliding anvil is disposed on the horizontal table and has a powder dispensing portion, a compacting portion, and a pick up portion. The anvil is movable between a filling position wherein the dispensing portion is above the cavity, a compacting position wherein the compacting portion is above the cavity, and a pick up position wherein the pick up portion is above the cavity. A rotary drive operates to move the compacting punch and the sliding anvil in a coordinated manner. A safety cover can cover a portion of the table and the sliding anvil during operation of the machine and interlock determines if the safety cover is in a closed position. A variable frequency drive controller operates to control the rotational speed of the rotary drive and is in communication with the interlock. The drive control has a control panel including a mode control, a run control, a direction control, and a speed control. The drive control has a run mode and a set up mode that are selectable using the mode control. When the drive control is in the run mode, the run control operates to cause the rotary drive to continuously rotate at a rotational speed in a first range of speeds only when the interlock indicates that the safety cover is closed. The run control requires only a single manipulation to cause continuous rotation. While in the run mode, the speed control operates to increase or decrease the rotational speed of the rotary drive within the first range of speeds. When the drive control is in the set up mode, the run control operates to cause the rotary drive to rotate at a second speed that is less than the first range of speeds but does so only while the run control is manipulated. The rotary drive stops when the run control is released. Therefore, the rotary drive may be jogged. The run control is operable to cause rotation of the rotary drive when the interlock indicates the safety control is closed as well as when the interlock does not indicate that the safety cover is closed. While in the set up mode, the direction control is operable to control the direction of rotation of the rotary drive.